Shoals vital to quality waves at Strad

Dec 5, 2012

The Terms of Reference for Professor Short's recent study on the impact of capital dredging of a channel for cruise ships has never been made available in the public domain for analysis, so the Terms may have been very narrow. And other than general statements by the Mayor, Professor Short's report remains a GCCC secret.

It is understood Short only conducted static modelling on the basis that a dredged channel ocean-side of the Seaway and the surrounding topographical features would remain the same after the initial capital dredging. Reports, using dynamic modelling research methods, however, reveal that the sand moving from south to north across the Seaway entrance which currently nourishes the Straddie offshore shoals (ebb-tide delta) will fall into the dredged channel rather than being transported to the shoals. After large weather events (heavy waves) the shoals will be depleted but no longer re-nourished by the northerly moving sand which will fall into the dredged channel south of the shoals.

Thus, over time, the waves WILL be degraded on Straddie given that both Short and SOSA researchers agree that these shoals are crucial in their influence on the quality (shape, size, direction, location) of South Straddie's waves. In other words, the dredged channel will cause the sand tap that currently feeds the shoals to be turned off. Short's report may be correct in its predictions for a dredged channel with surrounding areas which remain static (unchanging) but the Seaway currents, off-shore littoral sand movement, ocean waves and weather events on the GC are not static and neither will be the dredged channel. And in his research Short appears to have NOT addressed the 'lifetime of dredging' (GCCC Oct. 2012) required to keep the outer-channel open.

Short also responded to questions from a SOSA supporter with the claim that 'Pre-1984 the Nerang entrance was extremely hazardous and TOS did not exist.' This is not correct and the briefest of socio-historical research by Short; that is, interviews with members of North End Boardriders, some of whom have been surfing the Spit and Straddie for over 40 years, would have revealed the following:

Waves did exist on South Straddie prior to the Seaway walls being constructed (1984-86). The waves were of a similar quality and type to those waves currently found on the beaches at Phillip Park, south of the sand-pumping jetty on the Spit. Prior to 1984, surfers would often paddle over to South Straddie to get away from crowded surf breaks on the Spit. The Nerang sandbar itself was described to SOSA by one North End Boardrider as, 'world class on its day but a very advanced and difficult wave and the waves at Nerang Head (northern end of Spit) were better then than they are today'.

Short's suggestion that 'TOS is a constructed surf break' is also an inadequate description of South Straddie because waves did exist there before the Seaway walls were constructed. These waves were enhanced 'accidentally' by the combination that now exists between nature and the northerly littoral sand movement, formation of an ebb-tide delta, Broadwater currents and the effects of the Seaway walls and the sand-pumping program. The world-class wave at Kirra was also an 'accidental' but effective combination of man-made and natural elements but when man interfered by shortening the groin and pumping excessive amounts of sand north from the Tweed by-pass, the quality of Kirra was grossly diminished.

And whether a world-class surf break is totally natural or a combination of man-made and natural elements is irrelevant, if waves work and help to bring $235 million (Lazarow 2006) in recreational surfing tourist dollars annually to the Gold Coast, why muck around with them and potentially ruin them.

TOS alone brings $18-30 million annually (Lazarow 2006) to the north Gold Coast and a cruise terminal will bring only $4.6 million annually (Qld. Govt. Initial Advice Statement 2005) and that's if 30 ships per year visit the Gold Coast. SOSA's analysis of the Malaysian Navigational Simulation report (Qld. Govt. 2004) revealed this number of visits is not possible because of the weather-event nature of the Gold Coast where wind speeds and directions, current speeds and wave heights make it impossible for ships up to 300 metres in length to safely navigate the proposed outer-channel, Seaway and Broadwater on many days of the year. Most ships since 2004 are now 300-350 metres in length which makes the prospect of safe navigation of any ship even less probable today.

Other unanswered questions which appear to be outside the Terms of Reference for Short's research and report to the GCCC regarding TOS include:

To accommodate cruise vessels entering and passing through the Seaway after the initial dredging to 12 metres LAT (required depth in 2006, but now 15 metres LAT to cater for 350 metre vessels) for up to 1km to sea and through the Seaway, maintenance dredging will be required on a regular basis; or a combination of maintenance dredging/extension of the southern Seaway wall by 400-600 metres/ sand-pumping of an additional 300,000 cubic metres of sand per year on top of the current 500,000 cm per year (Qld Govt. IAS 2005). What effect will this have on Straddie water quality and therefore wave quality through turbidity?

With increased turbidity do you anticipate an increase in dangers to surfers of shark attack paddling across the Seaway to Straddie and on the surf break due to the proximity the bull shark 'playground' on the east end of the North Seaway Wall and their preference for mouthing prey in turbid water?

What are the likely effects on water quality and marine habitat in the Seaway and surf break with the dredging of the Seaway which will expose bedrock sediment in the form of coffee-rock?

What are the dangers presented to surfers paddling across the seaway with the inevitable increase in Seaway current speeds associated with dredging of the Seaway channel?

Questions which apply to the impacts of cruise-ship terminals proposals on both North-Kirra/Kirra and the Spit/Broadwater:

What will be the effect on water quality through turbidity caused by cruise ship props and bow/stern thrusters and/or the props of up to 2 pilot vessels (tugs) assisting cruise ships as ships pass through the outer channel and Seaway or the waters off Kirra?

What are the likely environmental, tourism, social and economic dangers and outcomes of a shipping accident near or in the Seaway/ Broadwater or off Kirra? i.e. run aground, blocking normal tidal flow of Seaway currents or ocean currents; grey water/sewage spillage; mechanical breakdown; penetration of hull through collision with Seaway wall or running aground off Kirra?

What are the time and geographic restrictions imposed by security zones and laws in relation to paddling across the Seaway to Straddie surf-break and accessing Straddie by PWC's, tinnies etc. or on the foreshores and water surrounding Kirra and North Kirra while cruise and military vessels are entering, departing and berthing on the Gold Coast? (with reference to ISPS codes and other local and international maritime and military laws).

What will be the effect on traffic flows to cater for buses, taxis, service vehicles/trucks on the Spit or Kirra and North Kirra in relation to cruise ship visits? How will this affect surfers trying to get to the north end of the Spit by road access to Spit and Straddie surf or to Kirra and North Kirra beaches?

What effects will dredging and the accommodation of cruise vessels have on the experience of seeing dolphins, whales etc. as a part of the surf experience?

TOS has worked as one of the most consistent quality beach breaks in the world for the past 25 years since completion of the Seaway in 1986. It works by a combination of luck, man-made impositions and natural forces. Even to tinker with it may degrade or ruin the quality of surf it currently produces.

The quality of Kirra was also a combination of nature and man-made structures coming together by accident and/or happy coincidence to produce the world's best point break. So shouldn't the adage be: